The Justice Department’s chief peacekeeper is on his way to embattled Ferguson, Mo.

Usually, Grande H. Lum flies under the radar. As head of the department’s Community Relations Service, the Harvard Law School graduate is an experienced mediator, more diplomat than prosecutor. The agency he heads was established under the 1964 Civil Rights Act, with the stated mission to aid communities “in resolving disputes, disagreements, or difficulties relating to discriminatory practices based on race, color, or national origin which impair the rights of persons in such communities.”

“These officials will continue to convene stakeholders whose cooperation is critical to keeping the peace,” Attorney General Eric Holder said.

It’s a small agency, with an annual budget of about $12 million. As the agency notes in its most recent annual report, its mediators have been involved in some of the hottest disputes in the nation’s history, from the Civil Rights movement to the 2012 Trayvon Martin shooting in Florida.

In 2012, the agency completed 728 cases. “Tensions over hate incidents or crimes” accounted for many of the cases; a total of 67 dealt with “police-community relations.”

In Springfield, Mo., that year, for instance, the mediators presented an “Arab, Muslim, and Sikh Cultural Awareness Program” following a hate incident at a local Islamic Center.

In Florida, following Martin’s shooting, the mediators reported that they “negotiated a peaceful end to a student-led sit-in” and “facilitated discussions between city officials and demonstrators; established an alliance of clergy leaders to help bring the city’s communities together (and) implemented rumor-control measures,” among other steps.

The agency’s work in Florida also drew some feverish criticism from conservatives, some of whom contended the Justice Department was secretly organizing rallies against the man who shot Martin, George Zimmerman. Keep an eye on Fox News Channel to see if similar allegations are revived in Ferguson.